The Avro 730 was a planned Mach 3 reconnaissance aircraft and strategic bomber that was being developed by Avro Aircraft for the Royal Air Force (RAF). It had been originally envisioned as a very high-speed aircraft to perform aerial reconnaissance missions, conforming with the requirements of Air Ministry Specification OR.330. Avro subsequently decided to modify the design of the proposed 730 in order to accommodate its arming with nuclear weapons; this change therefore meant that the type would be able to perform the nuclear weapons delivery mission as well, which had been called for under Air Ministry Specification RB.156T which sought a high speed reconnaissance-bomber aircraft. If the Avro 730 had proceeded into service, it would have replaced the V bombers as the primary airborne platform as a part of Britain's nuclear deterrent. In early 1957, the Avro 730 was abruptly cancelled, along with the development of a number of other crewed aircraft, as a consequence of the 1957 Defence White Paper. Part of the reason for the cancellation was the perception that by the time it would enter service, Soviet anti-aircraft capabilities would have improved to the point where it would not be able to succeed in its mission; a preference for missile development over crewed aircraft was another factor. A successor high-speed bomber flying at low level to evade radar would be developed to meet Air Ministry Specification GOR.339, designated as the BAC TSR-2; however, this too would be eventually cancelled. Development Origins Following the end of the Second World War and facing the threats of the newly emerging Cold War, the Royal Air Force (RAF) was keen to not only preserve but to strengthen its strategic capabilities. In particular, RAF Bomber Command sought to replace its inventory of wartime bombers with more capable models that would take advantage of the latest technologies, such as jet propulsion and nuclear weapons. During the late 1940s and early 1950s, an entirely new jet-powered bomber fleet comprising three aircraft, the Vickers Valiant, the Avro Vulcan, and Handley Page Victor, which were collectively known as the V-bombers, were developed and introduced to service with the RAF. The V-bombers were purpose-built to be armed with the first generation of Britain's nuclear weapons, designated as Blue Danube, and served as the airborne carriers of Britain's nuclear deterrence for many years. Even as the V-bombers were being introduced, the RAF had identified a need for